Class: Liquor::Emitter

Inherits:
Object
  • Object
show all
Includes:
ASTTools
Defined in:
lib/liquor/emitter.rb

Constant Summary collapse

OPERATORS = 
{
  :uminus => '-',  :not   => '!',
  :mul    => '*',  :div   => '/',  :mod => '%',
  :plus   => '+',  :minus => '-',
  :eq     => '==', :neq   => '!=',
  :lt     => '<',  :leq   => '<=',
  :gt     => '>',  :geq   => '>=',
  :and    => '&&', :or    => '||',
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(context) ⇒ Emitter

Returns a new instance of Emitter.



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# File 'lib/liquor/emitter.rb', line 7

def initialize(context)
  @context  = context
  @compiler = context.compiler
  @buffer   = ""
  @current_capture_var = ""
end

Instance Attribute Details

#compiler ⇒ Object (readonly)

Returns the value of attribute compiler.



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# File 'lib/liquor/emitter.rb', line 5

def compiler
  @compiler
end

#context ⇒ Object (readonly)

Returns the value of attribute context.



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# File 'lib/liquor/emitter.rb', line 5

def context
  @context
end

Instance Method Details

#boolean_binop(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 182

def boolean_binop(node)
  lhs, rhs = nvalue(node)
  "(#{convert_boolean(lhs)} #{OPERATORS[ntype(node)]} #{convert_boolean(rhs)})"
end

#boolean_unop(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 187

def boolean_unop(node)
  expr, = nvalue(node)
  # converts by itself
  "#{OPERATORS[ntype(node)]}(#{expr(expr)})"
end

#buf ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 18

def buf
  "_buf#{@current_capture_var}"
end

#call(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 112

def call(node)
  lhs, rhs = nvalue(node)
  name,    = nvalue(lhs)
  arg, kw  = nvalue(rhs)

  if !@context.function? name
    raise NameError.new("undefined function `#{name}'", nloc(lhs))
  end

  function = @context.compiler.function(name)
  if function.unnamed_arg && arg.nil?
    raise ArgumentError.new("unnamed argument is required, but none provided", nloc(rhs))
  elsif !function.unnamed_arg && !arg.nil?
    raise ArgumentError.new("unnamed argument is not accepted, but is provided", nloc(arg))
  else
    function.mandatory_named_args.each do |kwarg,|
      unless kw.include? kwarg
        raise ArgumentError.new("named argument `#{kwarg}' is required, but none provided", nloc(rhs))
      end
    end
    kw.each do |kwarg, kwval|
      if !function.mandatory_named_args.include?(kwarg) &&
         !function.optional_named_args.include?(kwarg)
        raise ArgumentError.new("named argument `#{kwarg}' is not accepted, but is provided", nloc(kwval))
      end
    end
  end

  if arg.nil?
    args = [ "nil" ]
  else
    args = [ expr(arg) ]
  end

  kw = kw.map do |kwarg, kwval|
    "#{kwarg.inspect} => #{expr(kwval)}"
  end
  args << "{ #{kw.join(", ")} }"

  args << nloc(node).inspect

  "@functions[#{name.inspect}].call(#{args.join(', ')})"
end

#capture ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 286

def capture
  previous_capture_var = @current_capture_var
  @current_capture_var = @buffer.lines.count.to_s # unique id
  out! %Q{#{buf} = ""\n}

  yield

  buf
ensure
  @current_capture_var = previous_capture_var
end

#cat!(string) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 298

def cat!(string)
  out! "#{buf} << (#{string})\n"
end

#check_external(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 227

def check_external(node)
  "Runtime.external!(#{expr(node)}, #{nloc(node).inspect})"
end

#check_integer(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 197

def check_integer(node)
  "Runtime.integer!(#{expr(node)}, #{nloc(node).inspect})"
end

#check_interp(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 231

def check_interp(node)
  "Runtime.interp!(#{expr(node)}, #{nloc(node).inspect})"
end

#check_string(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 206

def check_string(node)
  "Runtime.string!(#{expr(node)}, #{nloc(node).inspect})"
end

#check_tuple(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 215

def check_tuple(node)
  "Runtime.tuple!(#{expr(node)}, #{nloc(node).inspect})"
end

#compile_block(block) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 258

def compile_block(block)
  block.each do |node|
    case ntype(node)
    when :plaintext
      cat! string(node)

    when :interp
      expr, = nvalue(node)
      cat! check_interp(expr)

    when :tag
      ident, args = nvalue(node)
      name, = nvalue(ident)

      unless @compiler.has_tag? name
        raise NameError.new("undefined tag `#{name}'", nloc(ident))
      end

      @compiler.tag(name).compile(self, node)

    else
      raise "unknown block-level node #{ntype(node)}"
    end
  end
rescue Liquor::Diagnostic => e
  @compiler.add_diagnostic e
end

#compile_toplevel(block) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 235

def compile_toplevel(block)
  compile_block(block)

  [
    %!lambda { |_env={}, _storage={}|\n!,
    %|  _buf = ""\n|,
    ([
      %|  |,
      @context.externals.map do |extern|
        @context.access(extern)
      end.join(", "),
      %| = |,
      @context.externals.map do |extern|
        %Q|_env[#{extern.inspect}]|
      end.join(", "),
    ] if @context.externals.any?),
    %|\n|,
    flush!,
    %|  _buf\n|,
    %|}\n|
  ].join
end

#convert_boolean(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 193

def convert_boolean(node)
  "!!(#{expr(node)})"
end

#env ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 14

def env
  '_env'
end

#equality_binop(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 177

def equality_binop(node)
  lhs, rhs = nvalue(node)
  "(#{expr(lhs)} #{OPERATORS[ntype(node)]} #{expr(rhs)})"
end

#expr(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 55

def expr(node)
  case ntype(node)
  when :ident
    ident(node)
  when :integer
    integer(node)
  when :string
    string(node)
  when :tuple
    tuple(node)
  when :plus
    plus(node)
  when :mul, :div, :mod, :minus,
       :lt, :leq, :gt, :geq
    integer_binop(node)
  when :uminus
    integer_unop(node)
  when :eq, :neq
    equality_binop(node)
  when :and, :or
    boolean_binop(node)
  when :not
    boolean_unop(node)
  when :index
    index(node)
  when :external
    external(node)
  when :call
    call(node)
  else
    raise "unknown node #{ntype node}"
  end
end

#external(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 89

def external(node)
  target, method, args = nvalue(node)
  name, = nvalue(method)

  if args
    arg, kw = nvalue(args)

    if arg.nil?
      out_args = [ "nil" ]
    else
      out_args = [ expr(arg) ]
    end

    kw.each do |kwarg, kwval|
      out_args << "#{kwarg.inspect} => #{expr(kwval)}"
    end
  else
    out_args = []
  end

  "#{check_external(target)}.liquor_send(#{name.inspect}, [ #{out_args.join(", ")} ], #{nloc(method).inspect})"
end

#flush! ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 307

def flush!
  @buffer
ensure
  @buffer = ""
end

#ident(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 26

def ident(node)
  name, = nvalue(node)

  case @context.type name
  when :builtin
    case name
    when 'null';  'nil'
    when 'true';  'true'
    when 'false'; 'false'
    end
  when :variable
    @context.access name, nloc(node)
  when :function
    raise NameError.new("using function `#{name}' as a variable", nloc(node))
  when :free
    raise NameError.new("identifier `#{name}' is not bound", nloc(node))
  end
end

#index(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 156

def index(node)
  lhs, rhs = nvalue(node)
  "#{check_tuple(lhs)}[#{check_integer(rhs)}]"
end

#integer(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 201

def integer(node)
  value, = nvalue(node)
  value
end

#integer_binop(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 167

def integer_binop(node)
  lhs, rhs = nvalue(node)
  "(#{check_integer(lhs)} #{OPERATORS[ntype(node)]} #{check_integer(rhs)})"
end

#integer_unop(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 172

def integer_unop(node)
  expr, = nvalue(node)
  "#{OPERATORS[ntype(node)]}(#{check_integer(expr)})"
end

#out!(string) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 302

def out!(string)
  string = string.gsub /(^|\n)/m, '\1' + ("  " * @context.nesting)
  @buffer.concat string
end

#plus(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 161

def plus(node)
  lhs, rhs = nvalue(node)
  "Runtime.add!(#{expr(lhs)}, #{nloc(lhs).inspect}," +
    " #{expr(rhs)}, #{nloc(rhs).inspect})"
end

#storage ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 22

def storage
  "_storage"
end

#string(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 210

def string(node)
  value, = nvalue(node)
  value.inspect
end

#tuple(node) ⇒ Object 



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# File 'lib/liquor/emitter.rb', line 219

def tuple(node)
  value, = nvalue(node)
  code = value.map do |elem|
    expr elem
  end.join(", ")
  "[ #{code} ]"
end